Carbon balance studies of glucose metabolism in rat cerebral cortical synaptosomes.
Synaptosomes were isolated from rat cerebral cortex and incubated with [U-14C]-, [1-14C]- or [6-14C]glucose. Glucose utilization and the metabolic partitioning of glucose carbon in products were determined by isotopic methods. From the data obtained a carbon balance was constructed, showing lactate to be the main product of glucose metabolism, followed by CO2, amino acids and pyruvate. Measuring the release of 14CO2 from glucose labelled in three different positions allowed the construction of a flow diagram of glucose carbon atoms in synaptosomes, which provides information about the contribution of the various pathways of glucose metabolism. Some 2% of glucose utilized was calculated to be degraded via the pentose phosphate pathway. Addition of chlorpromazine, imipramine or haloperidol at concentrations of 10(-5) M reduced glucose utilisation by 30% without changing the distribution pattern of radioactivity in the various products.
D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism; D002250:Carbon Radioisotopes / Q000378:metabolism*; D002540:Cerebral Cortex / Q000378:metabolism*; D002952:Citric Acid Cycle; D005947:Glucose / Q000378:metabolism*; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D008297:Male; D010428:Pentosephosphates / Q000378:metabolism; D011619:Psychotropic Drugs / Q000494:pharmacology; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism; D011773:Pyruvates / Q000378:metabolism; D019289:Pyruvic Acid; D051381:Rats; D011919:Rats, Inbred Strains; D013574:Synaptosomes / Q000378:metabolism*
D000596:Amino Acids; D002250:Carbon Radioisotopes; D007773:Lactates; D010428:Pentosephosphates; D011619:Psychotropic Drugs; D011768:Pyruvate Dehydrogenase Complex; D011773:Pyruvates; D002245:Carbon Dioxide; D019344:Lactic Acid; D019289:Pyruvic Acid; D005947:Glucose